I find it sad that our games consoles don’t come with the ability for us to do with them as we please. Just look at the lifetime, success and market that grew up around the Commodore 64 just because when you switched it on it said "Ready".

You can still do this. It is called a Personal Computer. Look at the Atari/Coleco/Intelivision consoles of a similar era. None supported the above either.

Imagine what would be possible if you could plug in a keyboard and mouse into [..] a Wii and everything was available to you.

You can. I've done this. Even without Homebrew, the Wii will surf the web, has some kind of Flash and will play (in the UK) BBC iPlayer content directly on the console. Pretty sweet. The iPlayer interface is better than the one on other platforms (Virgin Cable/FreeView/Web) and snappy, given the relative sluggishness of the console.